A 62-year-old man with a weight of 134 kg (body mass index [BMI] of 40) and history of hypertension, diabetes, sleep apnea, claustrophobia, and 3-vessel coronary artery disease was scheduled for elective coronary artery bypass surgery. Once in the operating room, the resident placed an arterial line in the patient's left arm under local anesthesia. Because the patient was unable to tolerate the facemask oxygen (due to claustrophobia), the attending anesthesiologist gave him the anesthetic circuit, which had oxygen flowing at 10 liters per minute and asked him to keep it in his mouth and breathe through it (like snorkeling) to achieve pre-oxygenation.
The anesthesiologist then injected 2 mg of midazolam to sedate the patient. After about 5 minutes, the anesthesia team noticed that the patient was unresponsive, with shallow breathing. Breathing was assisted with facemask ventilation and…
